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Commit 96a4c8d5 authored by Alex Deucher's avatar Alex Deucher Committed by Dave Airlie
Browse files

drm/radeon/kms: fix i2c prescale calc on older radeons 



Should fix fdo bug 26430

Signed-off-by: default avatarAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent ae08819c

drivers/gpu/drm/radeon/radeon_i2c.c

+8 −9
Original line number Diff line number Diff line
@@ -183,11 +183,10 @@ static void set_data(void *i2c_priv, int data) 


static u32 radeon_get_i2c_prescale(struct radeon_device *rdev)

{

	struct radeon_pll *spll = &rdev->clock.spll;

	u32 sclk = radeon_get_engine_clock(rdev);

	u32 prescale = 0;

	u32 n, m;

	u8 loop;

	u32 nm;

	u8 n, m, loop;

	int i2c_clock;



	switch (rdev->family) {
@@ -203,13 +202,15 @@ static u32 radeon_get_i2c_prescale(struct radeon_device *rdev) 
	case CHIP_R300:

	case CHIP_R350:

	case CHIP_RV350:

		n = (spll->reference_freq) / (4 * 6);

		i2c_clock = 60;

		nm = (sclk * 10) / (i2c_clock * 4);

		for (loop = 1; loop < 255; loop++) {

			if ((loop * (loop - 1)) > n)

			if ((nm / loop) < loop)

				break;

		}

		m = loop - 1;

		prescale = m | (loop << 8);

		n = loop - 1;

		m = loop - 2;

		prescale = m | (n << 8);

		break;

	case CHIP_RV380:

	case CHIP_RS400:
@@ -217,7 +218,6 @@ static u32 radeon_get_i2c_prescale(struct radeon_device *rdev) 
	case CHIP_R420:

	case CHIP_R423:

	case CHIP_RV410:

		sclk = radeon_get_engine_clock(rdev);

		prescale = (((sclk * 10)/(4 * 128 * 100) + 1) << 8) + 128;

		break;

	case CHIP_RS600:
@@ -232,7 +232,6 @@ static u32 radeon_get_i2c_prescale(struct radeon_device *rdev) 
	case CHIP_RV570:

	case CHIP_R580:

		i2c_clock = 50;

		sclk = radeon_get_engine_clock(rdev);

		if (rdev->family == CHIP_R520)

			prescale = (127 << 8) + ((sclk * 10) / (4 * 127 * i2c_clock));

		else